FOOD, NUTRITION & CULTURE

‘Feeding oneself and one’s offspring is the first concern of all living creatures’

WHY IS THE ACQUISITION OF FOOD SO IMPORTANT?

• Question answered by the old adage ‘We are what we eat.’

• All living creatures need to ‘take in nutrients to live.’

• Nutrition – the science that deals with the body’s ability to transform nutrients found in FOOD into FUEL & FLESH.

Calories

Muscle&

Tissue

PERSPECTIVES ON NUTRITION

• To scientists, nutrition is the study of:– The nutrients found in foods – The body’s handling of

nutrients to maintain health

• Nutrients (some of which provide energy for processes in the body) are substances that can promote:– Growth – Maintenance– Repair

For many, nutrition is all about losing

weight!

OCTOPUS

MEXICAN FOODS

ACKEE AND

BREADFRUIT

PEARBUSH BUDS

WHAT IS FOOD?• Food is a conduit for nutrients.• It is one central thing about human experience that

can open up both our senses and our experiences to our place in the world.

– Alice Waters

Food is culturally defined, what is considered a food in

Culture A is not necessarily a food in Culture B.

THE NUTRIENTS• Whereas there are many different

foods. There are only six classes of nutrients namely:– carbohydrates (CHO)– proteins – fats – vitamins – minerals – water

• Usually, more than one class of nutrients is represented in a food (e.g., (CHO, fats, proteins, water, minerals [e.g., Ca] and vitamins [e.g., Vitamin D] are in milk.

TYPES OF NUTRIENTS protein

Vitamin c

Fatty acids

–Organic (with C- C or C- H bonds)

•CHO, •Proteins•Fats•Vitamins

waterSodium and Chlorine ions

–Inorganic •Water •Minerals.

ENERGY YIELDING NUTRIENTS

• Carbohydrates– glucose, (preferred

energy source) fructose and galactose

• Fats– fatty acids and

glycerol

• Proteins– amino acids

• Vitamins - only organic nutrient that does not supply energy but is needed to get energy from foods.

• Essential nutrient - body cannot make enough of and must get from food.

• Some dietary and lifestyle practices (smoking, inactivity, drinking alcohol) are risk factors for many health conditions.

• Substances (non-nutrients) in foods are phytochemicals that give foods the characteristic taste and smell.

MORE FOOD RELATED FACTS ….

FOOD CHOICES

• Advertising• Availability• Convenience• Economy• Comfort• Ethnicity• Habit

• Personal Preference• Positive Associations• Geographical location• Social Pressure• Values and beliefs• Body weight

• Select foods to provide adequate amounts of nutrients and energy!

• When humans eat, foremost in their minds is that they are consuming foods, not nutrients!

• The following influence food choices:

pizz

a

• Nutritional Value

CHALLENGE OF CHANGING FOOD HABITS

• Food is about more than feeding the body. It is embedded in family life, culture and religious ritual.

• Food has always been the most direct, intimate tie to a nurturing earth and a primary means of bonding with each other.

• Food has helped us to know where and who we are.

• Digestion – process of breaking food into small substances to be absorbed by the body and subsequently used for fuel, growth, maintenance and repair.

RELEASING NUTRIENTS FROM FOOD

Simple (e.g., phagocytosis- engulf and form food vacuoles in which food is broken down in the unicellular amoeba).

Complex (e.g., cooking and chewing food before introducing it to the sophisticated multi-organ, digestive system in multi-cellular humans).

PRODUCTS OF DIGESTION(Energy Nutrients)

CHO

FATS

PROTEINS

GLUCOSEFRUCTOSEGALACTOSE

FATTY ACIDS

GLYCEROL

AMINO ACIDS

Gastro-intestinal

System

• Food energy measured in calories.

• A calorie is not a component of food.

1g fat =

9 calorie

s

1g CHO = 4 calories

1g protein = 4

calories

1 g alcohol = 7 ca

lories

(alcohol is

not a

nutrient)

MEASURING FOOD ENERGY

ENERGY

• Plants use the sun’s energy to combine carbondioxide and water to form glucose and oxygen.

6H2O + 6CO2 = C6H12O6 + 6O2

• Plants store energy as starch.

• Humans eat plants and other animals that have also eaten plants.

The Cycle of life begins with

the sun!

The Energy Cycle

THE ABC… OF A NUTRITIOUS DIET

• Adequacy• Balance• Calorie control• Moderation• Nutrient Density• Variety

DIETARY GUIDELINES

I am inebriated!

Not to be emulated!

NUTRITION AND HEALTH• Health professionals agree that the overall

composition of the diet has an important effect on health.

• Eating too much fat, sat. fat and cholesterol and not eating enough vegetables, fruits, and fiber has been linked to an increase in heart disease and other cancers.

• The federal government constantly revises its official U.S. Dietary Guidelines for Americans to help consumers choose a healthy diet.

• These guidelines make Recommendations for Americans 2 years of age and older.

NUTRITION GOALS

Disease Related• Reduce coronary heart disease• Reduce cancer deaths• Decrease incidence of diabetes• Reduce prevalence of

osteoporosis and• Reduce dental caries

HOW MUCH FOOD DO WE NEED?

RDA (recommended dietary allowances)• Primary nutrient intake standards for US

for many years.

DRI (dietary reference intake)• Recently replaced RDA as primary

standards• Expands on RDAs

DRI GROUPS (dietary reference intake)

• Recommendations made for various age and gender groups as follows: – Men– Women– Pregnant and lactating women– Children– Teens– Elderly

MEAL PLANNING GUIDES

• Food group plan

• Exchange system

•Daily Food Guide – (Food Pyramid)

EXCHANGE SYSTEM

• Originally developed for diabetics• Lists of foods that can be

exchanged• Food values are approximations• User makes an educated

approximation

= =

• Let the Pyramid guide your food choices.

• Choose a variety of grains daily, especially whole

grains.• Choose a variety of fruits and vegetables daily.• Keep food safe to eat!

CHOOSING FOODS ………

FOOD LABELS• Food labels provide the following

information:– Common name of product.– Name and address of manufacturer,

packer or distributor.– Net contents (wt, measure or count).– Nutrient content of product– Serving size– Servings per container– Calories/calories from fat– Nutrient amounts and percentages

of Daily Values– Daily values and calories/gram

reminder– Ingredients

CHECK THE FOOD LABEL BEFORE YOU BUY

• Food labels have several parts:– Front panel,

• Added nutrients (e.g., “enriched grain/pasta” means thiamin, riboflavin, niacin, iron, and folic acid have been added.

– Nutrition Facts, – Ingredients list,

•What’s in the food including e.g., added fats, or sugars.

•Ingredients listed in descending order by weight.

USING THE NUTRITION FACTS

– Look at the % Daily Value (%DV) column to see whether a food is high or low in saturated fat, cholesterol, sodium.

– If you want to consume more of a nutrient (e.g., Calcium), choose foods with a higher %DV.

– Foods with 5%DV or less contribute a small amount of that nutrient. Those with 20% or more contribute a large amount.

• Nutrition Facts serving sizes may differ from Food Guide Pyramid (e.g., 2 ozs of dry macaroni yields about 1 cup cooked, or two [½ cup] Pyramid servings).

HELPFUL HINTS•    Use the Food Guide Pyramid to help select

healthy foods.•    Eat a variety of plant foods, including whole

grains, fruits, and vegetables.•   Eat some low-fat dairy products and low- fat

foods from the meat and beans group.•  Enjoy fats and sweets occasionally.

DIETARY ASSESSMENT

The following dietary assessment methods are used:

• 24-Hour recall• Food Record/Diary• Food Frequency Questionnaire

KEEPING TRACK………Food Record Do the following:• Record everything you

eat and drink for 3 consecutive days

• Amount (ozs, g)– Time eaten– Mood before and after each meal

• Note other things you did that same day

Chicken

Bread

QUIZHow many calories does this meal of 110 g of carbohydrates, 25 g of protein, 20 g of fat, and 5 g of alcohol?

a. 160 b. 345c. 560 d. 755

The Exchange System of

meal planning was

originally developed for

people with

a. terminal diseases.

b. diabetes.

c. cardiovascular disease.

d. life- threatening

obesity.

Gram for gram, which of the following provides the most energy?a. fatsb. alcoholc. proteinsd. carbohydrates

Teacher’sPet

Assignment:

Check the RDA (recommended dietary allowances) in your country, if any.

A+

REFERENCES

• Whitney E, Rolfes S. Understanding Nutrition. 7 th ed. New York: West Publishing Company; 1996.

• Lappé F, Lappé A. Hopes Edge: The Diet of a Small Planet. New York: Jeremy P. Tarcher/Putman, 2002.

• Google Image Search. Available at: http://www.google.com. Accessed June 2004.